Die casting and trimming machine



July 4, 1967 5. G. PEKROL DIE CASTING AND THIMMING MACH INE 3 Sheets-Sheet 1 Filed July 21. 1964 George 6. Pa kro/ INVENTOR.

July 4, 1967 G. G. PEKROL 3,328,853

DIE CASTING AND TRIMMING MACHINE Filed July 21, 1964 3 Sheets-Sheet 2 Fig. 3

46 r F 52 44 F 66' I w i 5 /2 74 /20 I8 I49 /44 George 6. Pe/rro/ INVENTOR.

Mm BY ym, 25%

July 4, 1967 I cs. G. P'EKROL 3,328,853

DIE CASTING AND TRIMMING MACHINE Filed July 21, 1964 5 s t s 5 i Fig. 4 p; 24 I60 /52 148. I 4,9 I28 .2 l2 44 4a l f it '54 48 g Q 82 Q 94 H v 90 0 v Gorge 6. Pekro/ IN VENTOR.

United States Fatent C 3,328,853 DIE CASTING AND TRIMMING MAUHINE George G. Pekrol, Newark, NJ. Trim Tool Company, Rte. 10 and Harrison Ave, Morris Plains, NJ. 07956) Filed July 21, 1964, Ser. No. 384,088 7 Claims. (Cl. 164--262) The present invention generally relates to a machine for die casting and trimming the castings formed thereby.

The present invention has for one of its objects the provision of a rotatable and elevatable turntable structure having a surface to surface engagement with a stationary part of a mold and forming a part of the gate structure which enables the article being cast to be elevated from the mold cavity and rotated with the turntable for movement to a trimming mechanism and a gate removing mechanism with there also being provided a conveyor for conveying the trimmings back to the molten metal pot.

Another object of the present invention is to provide a die casting and trimming machine that is completely automatic in operation in that closing of the mold cavity will actuate the mechanism for forcing molten metal through the sprue into the mold cavity after which the mold will be opened and the casting along with a turntable having the gate attached thereto is simultaneously elevated for an increment of movement and then the turntable is elevated above the point at which the ejector pins stop thus elevating the casting above the ejector pins and subsequently rotating the turntable an increment of movement, lowering the turntable for another casting operation and at the same time operating a trimming mechanism spaced circumferentially of the turntable for trimming the previously formed casting and at the same time operating a gate removing mechanism for removing the gate on the turntable for a subsequent casting operation.

A further object of the present invention is to provide a die casting and trimming machine in accordance with the preceding object and including hydraulically operated mechanical structures for effecting the movement of the components of the invention.

Yet another feature of the present invention is to provide a die casting and trimming machine which is simple in construction, easy to operate, safe and eficient in operation and relatively inexpensive to maintain and operate.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being bad to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a side elevational view of a die casting and trimming machine incorporating the components of the present invention therein;

FIGURE 2 is a plan view taken generally along section line 22 of FIGURE 1 illustrating the construction of the turntable and its relationship to the lower mold cavity;

FIGURE 3 is a sectional view taken generally along the longitudinal center line of the construction of FIGURE 2 illustrating the orientation of the mold cavities, the turntable, the elevating mechanism for the ejector pins, the turntable and trimming mechanism;

FIGURE 4 is a side elevational view illustrating the mechanism in one stage of its movement;

FIGURE 5 is a side elevational view similar to FIG- URE 4 but illustrating the mechanism in another stage of its movement; and

FIGURE 6 is a detailed sectional view taken substantially upon a plane passing along section line 66 of FIGURE 5 illustrating a ratchet mechanism employed for turning the turntable.

Referring now specifically to the drawings, the nu- 3,328,853 Patented July 4, 1967 meral 10 generally designates the machine of the present invention which has not been disclosed in its entirety but the structure which incorporates the present invention therein has been disclosed and includes a pair of vertical guide rods 12 which are supported from a suitable base (not shown) and which are interconnected at their upper ends by a cross member 14 having a power piston and cylinder assembly 16 connected thereto for operating an actuating rod 18 connected operatively to a slide 20 mounted on the guide rods 12 for reciprocal movement in relation to a supporting frame 22 that is stationarily mounted. The slide 20 includes the upper half of a mold 24 having an upper cavity 26 formed therein. Interconnecting the slide 20 and the upper cross member 14 is a link 28 and an L-shaped link 30 connected thereto. The link 28 is connected to the slide 20 by a pivot pin 32 and the link 30 is connected to the cross member 14 by a pivot 34 and the links 28 and 30 are connected by a pivot pin 36. The L-shaped link 30 is pivotally connected to a short link 38 that pivotally interconnects an actuating member 40 carried by the actuating rod 18 so that as the actuating member 40 reciprocates vertically, the linkage system will collapse to the dotted line position illustrated in FIGURE 1 and be extended when the slide 20 and mold 24 are lowered to the full line position illustrated in FIGURE 1 so that the links 28 and 30 are in alignment. A switch mechanism such as a microswitch 42 is mounted stationarily on one of the guide rods 12 or on a suitable bracket attached to the cross member 14 for engagement by the link 28 or any part of the linkage mechanism when it is in its full line position with the slide 20 lowered .80 that the mold 24 is lowered to its operative position so that the remainder of the operation of the machine will be initiated. This assures that before the molten metal is injected through the sprue into the mold cavity, the mold sections will be positively closed thus preventing escape of molten metal through the space between the molds when the molten metal is shot into the cavity.

Mounted on the supporting frame 22 is a bottom mold 44 having a cavity 46 in the upper surface thereof for matching with the cavity 26 to receive the molten metal to cast an article or casting 43. The lower mold 44 is provided with a recess 50 in its inner edge having an inclined surface 52 therein for matching engagement with a turntable 54 having an inclined peripheral surface 56 which is also polygonal so that the straight surface of the turntable will match the surface 52 of the mold 44.

The bottom mold 44 is provided with a passageway or sprue 58 therein which receives molten metal from a pot (see FIGURE 2). Each straight side edge of the turntable 54 is provided with a notch or passageway 60 which matches with the inclined surface 52 and which aligns with the passageway or sprue 58 for forming a continuation of the sprue for communication with the cavities 26 and 46 for enabling molten metal to be shot into the cavity. With this arrangement, a portion of the casting is retained on the turntable 54 as a gate as illustrated in FIGURE 3 and heating elements 62 are disposed in the bottom mold 44 adjacent the sprue or passageway 58 to prevent excessive cooling of this area of the machine.

The turntable 54 as illustrated is octagonal in shape and provides eight flat portions for registry with the inclined surface 52. The turntable or plate 54is attached rigidly to a rotatable and slidable sleeve 64 mounted on one of the guide rods 12 for both reciprocation and vertical movement.

Also mounted under the bottom mold 44 is an ejection plate 66 pivotally supported on a plate 68 by a pivot pin 70. The plate 66 includes ejection pins 72 which are elevatable through the bottom cavity 46 for ejecting the casting 48 therefrom. The plate 68 is rigid with a vertically reciprocating rod 74 having a rack gear 7-6 formed thereon for meshing engagement with a pinion gear '78- carried by a shaft 81). The shaft 80 extends horizontally and is provided with a quadrant gear 82 on the end thereof for engagement with a rack gear 84 forming a part of a piston and cylinder assembly 88. The rack gear 84 is of limited length and has suificient teeth to engage only the teeth on the quadrant gear 82 for moving the quadrant gear 82 through an increment of movement after which a smooth portion of the piston rod 86 will register with the segment gear 82 so that the segment gear 82 will not rotate but the rack gear 84 will pick up the segment gear 82 when it returns to its retracted position. Thus, as the piston rod 86 is extended from an initial position, the segment gear 82 will be rotated an increment of movement for elevating the ejector pins 72 for a predetermined distance such as one-half inch. Thereafter, the rack gear 84 will disengage from the segment gear 82 and the segment gear 82 will stay in place until the piston rod 86 is retracted at which time the rack gear 84 will again pick up the segment gear 82 for returning the pins 72 to lowered position. A flat stop member 90 is integral with gear 82 and engages with or registers with the smooth part of rod 86 for retaining the gear 82 in place for pick up by the rack gear 84 during its return movement.

Also mounted on the piston rod 86 is a rack gear 92 in meshing engagement with a second segment gear 94 which has teeth about a periphery thereof substantially twice the arcuate distance as the segment gear 82. The segment gear 94 is mounted on a shaft 96 which carries a drive pinion gear 98 thereon for meshing engagement with a reciprocating rack gear 180 for actuation thereof upon rotation of the shaft 96. The rack gear 101} is attached to a sleeve 102 which is rotatable on the sleeve 64 and is received in arecess formed therein so that the sleeve 102 is stationary insofar as rotation is concerned during rotation of the sleeve 64 but is reciprocal vertically for raising and lowering the sleeve 64. The rack gear 100 axially slides in a recess 104 in the form of a guide slot in the support frame 22 for retaining the rack gear 188' meshed with the gear 98.

Thus, during initial movement of the piston rod 86 from a retracted to an extended position, both segment gears 82 and 94 are rotated simultaneously an equal amount thus raising both the ejector pins 72 and the turntable 54 an equal amount such as one-half inch. During subsequent extended movement of the piston rod 86, the segment gear 82 will be disengaged from the rack gear 84 but the segment gear 94 will be still engaged with the rack gear 92 whereby further movement of the piston rod 86 will cause continued movement of the turntable 54 so that it is elevated above the ends of the ejector pin 72 as illustrated in FIGURE 3 so that it is then free to rotate without interference from the ejector pins. Thus, during the initial increment of movement, both the ejector pins and turntable moves together so that the casting 48 is removed from the cavity 46. Thereafter, the ejector pins 72 stop and the turntable 54 continues upwardly for a total movement of one inch thus clearing the casting 48 away from the ejecting pins 72 so that the turntable 54 and casting 48 may be rotated about the axis of the sleeve 64.

For rotating the sleeve 64, the sleeve is provided with axial extensions 186 on the lower end thereof supporting an annular ring 188 having a plurality of projecting ratchet teeth 110 thereon. Encircling the ratchet teeth 110 is an annular member 112 having a spring biased latch mechanism or pawl 114 mounted thereon for engagement with the ratchet teeth 110. A laterally extending lug 116 is provided on the ring 108 for engagement by a link 118 connected to a piston rod 120 actuated by suitable piston and cylinder assembly 122 for rotating the sleeve 64 after the turntable 54 has been elevated. As illustrated in FIGURE 6, there are eight ratchet teeth so that each increment of movement of the turntable will be properly gauged for alignment with the bottom part of the mold. A retaining pawl 124 is provided to prevent reverse movement of the turntable during arcuate movement of the ring 112 so that the turntable will be retained in place during operation of the rotating mechanism. Suitable controls are provided for operating the rotating mechanism after the piston rod 86 has been fully extended and the piston rod 86 will be retained in extended position until such time as the turntable 54 has been rotated one increment of movement after which the piston and cylinder assembly 122 and piston and cylinder assembly 88 may move to a retracted position which will lower the turntable 54 and ejector pins 72 and at the same time return the piston rod 128 so that the pawl 114 will engage the next ratchet tooth for a subsequent rotating operation.

As the machine operates, there will he a casting 48 supported from the various side edges of the turntable 54 until the castings reach a point directly opposite from the mold cavity 46 at which time they are engaged by a trimming mechanism generally designated by the numeral 126 which not only trims the casting but removes it from the turntable 54. The trimming operation is conducted when the turntable is lowered to its position so that the casting 48 to be trimmed is properly placed in the trimming mechanism 126.

The trimming mechanism 126 includes a vertically reciprocatnig carrier rod 128 slidably received in a sleeve 130 carried by the supporting frame 22 and having a rack gear 132 on the lower end thereof engaging with a drive pinion 134 mounted on a shaft 136 which has the other end thereof provided with a gear 138 in meshing engagement with a rack gear 140 mounted on a piston rod 142 that is operated by a piston and cylinder arrangement 144 which serves to elevate and lower the rod 128 when the trimming mechanism is operated which is operated simultaneously with either the lowering of the top mold 24 or the injection of the molten metal so that the turntable 54 will be retained in place with the casting 46 resting on a supporting surface 146 which may have any particular shape opening 147 therein for receiving the casting 48 and for enabling the casting to be trimmed and dropped onto a conveyor 149, bin or the like. The upper end of the rod 128 is provided with an olfset arm 148 having a depending guide rod 150 associated therewith slidable through an opening 151 in the support plate 146. Further, trimming elements 152 are supported from the arm 148 and the shape of the trimming elements 152 will vary with the shape and configuration of the casting 48 involved and this is also true of the supporting plate 146 which may be either flat or provided with a cushioning material for facilitating the trimming operation. The supporting plate 146 may be of such a size that the trimmings when trimmed from the casting 48 drop onto a suitable conveying mechanism 154 for returning the trimmed metal to the molten metal pot 156.

A structure for removing the gate 158 of metal from the notch 68 and the turntable 54 is provided between the trimming mechanism 126 and the molds for removing the gate 158 after the casting 48 has been removed. This mechanism includes a pin 160 mounted on the slide 20 for simultaneous operation with the trimming mechanism 126 for cleaning the turntable 54 so that it will be ready for the next casting operation. The gates 158 fall onto the conveyor 154 for return to the pot 156. The conveyor structures may be gravity chutes, belt conveyors or the like.

Also, a direct operating mechanism may be used for operating the trimming mechanism 126. A cylinder and piston assembly may be incorporated into the rod 128 for vertically reciprocating the oifset arm 148.

As illustrated in FIGURE 2, the molten metal pot 156 has a tapered discharge member 162 telescopically received in a pipe or sleeve 164 leading tothe mold cavity through sprue or passageway 58. For mounting the pot 156, there is provided a pair of mounting rods 166 extending through the upturned ends of L-shaped brackets 168 and provided with screw-threaded nuts 170 on the inner ends thereof for pulling the pot 156 toward the frame 22 thus securely mounting the pot 156 and also retaining the pot in proper relationship so that the discharge member 162 is engaged with the sleeve or pipe 164 in a sealed manner. Any suitable mounting mechanism for the pot 156 may be provided and the structure of the pot itself may vary as to size and construction and may be conventional insofar as the mechanism for retaining the metal therein molten and insofar as the molten metal injector means is concerned.

By returning the trimmings as well as the gates back to the pot, the accumulation of residual trimmings and gates as a normal by-product is eliminated thus eliminating the necessity of separate bins and handling of such trimmings and gates. Further, by continuously feeding back the trimmings and gates, this material is completely used thus reducing wasteage and enabling the previously melted material to be mixed with the newly melted material in a relatively minor proportion in a continuous manner to avoid the necessity of introducing a relatively large proportion of remelted material.

The foregoing is considered as illustrative only of die principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new as is follows:

1. A die casting and trimming machine comprising a stationary lower mold, a movable upper mold, said mold having facing cavities, a rotatable turntable associated with said mold for forming a portion of the sprue in supporting a casting, said lower mold having ejector pins for ejecting the casting therefrom, and means simultaneously elevating the ejector .pins and turntable an initial increment of movement and subsequently elevating the turntable beyond the point of elevation of the ejector pins for separating the casting from the ejector pins, means for rotating the turntable multiple increments of unidirectional rotational movement for cooling the casting and then lowering the turntable and ejector pins for a subsequent castnig operation, a trimming mechanism including a supporting plate for the casting for supporting the casting when the turntable is lowered, means for trimming the casting when supported on the support plate, said turntable including a plate having a plurality of segments selectively alignable with the mold during sequential unidirectional increments of movement.

2. The structure defined in claim 1 wherein said means for rotating the turntable includes a plurality of ratchet teeth connected to the turntable, and pawl means engaging selective ratchet teeth for rotating the turntable a predetermined increment of unidirectional movement.

3. In a machine for die casting and trimming a casting formed by relatively movable molds having facing mold cavities, that improvement comprising rotatable means having a plurality of circumferentially arranged casting support areas for sequential alignment with the mold cavity, means rotating said rotatable means unidirectionally in increments of movement corresponding to the circumferential extent of each support area, and means trimming and separating the casting at a location circumferentially of the rotatable means requiring a multiple of increments of unidirectional movement of the rotatable means to move a support area and casting from the mold cavity to the trimming means to enable cooling of the casting.

4. The structure as defined in claim 3 together with means spaced circumferentially of the rotatable means from the trimming and separating means for removing residual waste portions of the casting from each support area of the rotatable means.

5. The structure as defined in claim 3 wherein one of said molds is stationary and the other movable, said rotatable mean-s also being axially movable in relation to the molds, and means operating said rotatable and axially movable means independent of movement of the movable mold.

6. The structure as defined in claim 5 wherein said rotatable and axially movable means is in the form of a plate with each support area thereon being defined by a straight peripheral segment.

7. The structure as defined in claim 6 wherein said stationary mold includes a recess receiving a support area on the plate with the outer surface of the plate being flush with the surface of said mold having the cavity therein, said support area including a passage communicating with the cavity for receiving molten metal when forming the casting and forming a support for the casting when removed from the mold.

References Cited UNITED STATES PATENTS 1,716,737 6/ 1929 Ramsden 22.21 2,848,770 8/ 1958 Schuchardt 22-94 3,137,905 6/ 1964 Steinman et al. 2294 J. SPENCER OVERHOLSER, Primary Examiner. R. BALDWIN, Assistant Examiner. 

1. A DIE CASTING AND TRIMMING MACHINE COMPRISING A STATIONARY LOWER MOLD, A MOVABLE UPPER MOLD, SAID MOLD HAVING FACING CAVITIES, A ROTATABLE TURNTABLE ASSOCIATED WITH SAID MOLD FOR FORMING A PORTION OF THE SPRUE IN SUPPORTING A CASTING, SAID LOWER MOLD HAVING EJECTOR PINS FOR EJECTING THE CASTING THEREFROM, AND MEANS SIMULTANEOUSLY ELEVATING THE EJECTOR PINS AND TURNTABLE IN INITIAL INCREMENT OF MOVEMENT AND SUBSEQUENTLY ELEVATING THE TURNTABLE BEYOND THE POINT OF ELEVATION OF THE EJECTOR PINS FOR SEPARATING THE CASTING FROM THE EJECTOR PINS, MEANS FOR ROTATING THE TURNTABLE MULTIPLE INCREMENTS OF UNIDIRECTIONAL ROTATIONAL MOVEMENT OF COOLING THE CASTING AND THEN LOWERING THE TURNTABLE AND EJECTOR PINS FOR A SUBSEQUENT CASTING OPERATION, A TRIMMING MECHANISM INCLUDING A SUPPORTING PLATE FOR THE CASTING FOR SUPPORTING THE CASTING WHEN THE TURNTABLE IS LOWERED, MEANS FOR TRIMMING THE CASTING WHEN SUPPORTED ON THE SUPPORT PLATE, SAID TURNTABLE INCLUDING A PLATE HAVING A PLURALITY OF SEGMENTS SELECTIVELY ALIGNABLE WITH THE MOLD DURING SEQUENTIAL UNIDIRECTIONAL INCREMENTS OF MOVEMENT. 